text: /****************************************************************************
   * arch/arm/src/sam34/sam_userspace.c
   *
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.  The
   * ASF licenses this file to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance with the
   * License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
   * License for the specific language governing permissions and limitations
   * under the License.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <stdint.h>
  #include <assert.h>
  
  #include <nuttx/userspace.h>
  
  #include "sam_mpuinit.h"
  #include "sam_userspace.h"
  
  #ifdef CONFIG_BUILD_PROTECTED
  
  /****************************************************************************
   * Pre-processor Definitions
   ****************************************************************************/
  
  /****************************************************************************
   * Private Data
   ****************************************************************************/
  
  /****************************************************************************
   * Private Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: sam_userspace
   *
   * Description:
   *   For the case of the separate user-/kernel-space build, perform whatever
   *   platform specific initialization of the user memory is required.
   *   Normally this just means initializing the user space .data and .bss
   *   segments.
   *
   ****************************************************************************/
  
  void sam_userspace(void)
  {
    uint8_t *src;
    uint8_t *dest;
    uint8_t *end;
  
    /* Clear all of user-space .bss */
  
    DEBUGASSERT(USERSPACE->us_bssstart != 0 && USERSPACE->us_bssend != 0 &&
                USERSPACE->us_bssstart <= USERSPACE->us_bssend);
  
    dest = (uint8_t *)USERSPACE->us_bssstart;
    end  = (uint8_t *)USERSPACE->us_bssend;
  
    while (dest != end)
      {
        *dest++ = 0;
      }
  
    /* Initialize all of user-space .data */
  
    DEBUGASSERT(USERSPACE->us_datasource != 0 &&
                USERSPACE->us_datastart != 0 && USERSPACE->us_dataend != 0 &&
                USERSPACE->us_datastart <= USERSPACE->us_dataend);
  
    src  = (uint8_t *)USERSPACE->us_datasource;
    dest = (uint8_t *)USERSPACE->us_datastart;
    end  = (uint8_t *)USERSPACE->us_dataend;
  
    while (dest != end)
      {
        *dest++ = *src++;
      }
  
    /* Configure the MPU to permit user-space access to its FLASH and RAM */
  
    sam_mpuinitialize();
  }
  
  #endif /* CONFIG_BUILD_PROTECTED */
  